Mastic floor tile



Patented June 18, 1940 UNITED STATES MASTIC FLOOR TILE Joseph Rivkin, Pittsburgh, and Robert C. Scheib, Avalon, Pa., assignors to The Neville Company, Pittsburgh, Pa., a corporation of Pennsylvania No Drawing. Application January 11, 1937, Serial No. 120,140

4 Claims.

This invention relates to mastic floor tile, and it is among the objects of the invention to provide mastic tile having particularly desirable temperature-susceptibility properties, which may be made in the lighter colors, of uniform quality, and without material change in existing procedures.

Mastic floor tile consists essentially of filler, pigment, or color, and a thermo-plastic organic cementing material which acts to bind the fillers and pigments or colors. fhe properties of the tile aredependent in large part upon the binder, which should be plastic and yield a tile which is neither too brittle nor too soft at normal temperatures of use, and which shows a minimum of softening at any temperature above normal to which it may be ordinarily subjected. Consequently the binder must retain its consistency, in terms of hardness and pliability, over a relative- 13/ wide temperature range, being of the proper hardness and pliability at normal temperature, not becoming too brittle at ordinarily depressed temperatures, nor too soft at ordinarily elevated temperatures.

The pliability of such binders at the temperature of use is gauged ordinarily by the penetration test, in which there is measured the distance which a standard needle under a standard load will penetrate into the material at a standard temperature in a standard length of time. The penetration values necessary differ according to the particular applications, but for any particular use the penetration value can not be below a certain minimum. In the production of mastic floor tile, for example, it is generally specified that the binder shall have a melting point of at least 0., determined by the ring and ball method, and a penetration of at least 3, determined by the needle method using a gm. load at 25 C. for five seconds.

Heretofore in the manufacture of darker colored floor tile these requirements have been supplied by asphaltic. binders, such as blown petroleum asphalt. The black color of the asphalts pre-' eludes their use, however, for the manufacture of lighter colored tile, and even in the production of the darker colored tile it makes necessary the use of rather high proportions of coloring materials, which increases the costs of the tile.

The trade has recognized the need fora lighter colored binder possessing temperature-susceptibility properties similar to those provided by blown asphalt. Most resinous materials available ior such use do not provide the necessary properties, as just described, because of their susceptibility to the influence of temperature. Generally speaking, if the resins are sufl'iciently high melting to retain the firmness desired at the higher temperatures occurring in use, they are' too brittle at the lower temperatures, or if sufficiently non-brittle at the lower temperatures they 5 become too soft at elevated temperatures such as may be encountered.

Gne mode of obtaining lighter colored binders whose temperature-susceptibility properties resemble those of blown asphalt has been by combining hard and brittle thermo-plastic resins with fatty acid pitches. The resulting mass possesses temperature-susceptibility properties resembling those of blown petroleum asphalt, but its use involves the disadvantages that the fatty acid pitches show poor resistance to alkalies, and they can not be obtained in uniform quality. These characteristics are particular disadvantages in connection with floor tile because alkaline detergents thus may cause unduly rapid destruction of the tile, and because control of manufacturing operations becomes complicated due to the nonuniformity of the pitches.

We have discovered that the material obtained by distilling various amounts of oil from pure still 25 residues provides a thermo-plastic binder that is especially useful in the production of mastic floor tile, not only for providing the necessary temperature-susceptibility properties, but also in. repressing or eliminating the foregoing and other disadvantages. For instance, the residue obtained by distilling a portion of the oils from pure still residues, used in the practice of the present invention, is non-saponifiable, whereby the resultant tile are resistant to the action of the detergents ordinarily used in cleaning floors. Also, the material can be supplied of uniform quality, thus rendering production operations simpler. Again, these binding materials, and the tile compositions made from them, are lighter in color than asphalts, thus supplying the need in the trade.

The term pure still residues has reference to the material left in the stills in the purification of the cuts resulting from the fractionation of the 45 light oils recovered in the operation of by-product coke ovens. More specifically, the common practice is toscrub the coke oven gases with a high boiling petroleum wash oil to remove the aromatic light oils in the form of a solution in the wash oil. The solution is then distilled to produce a mixture of light oils, chiefly benzol, toluol, xylol, and naphtha, which mixture is then fractionated to obtain impure cuts of the individual constituents. These crude fractions, or cuts, after having been acid washed and subsequently neutralized with alkali, are then distilled in the socalled pure stills to produce commercially pure solvents. The residues in the pure stills contain 5 complex mixtures of polymerized materials and high boiling oils, together with inorganic, or mineral, matter, and these residues are termed in the trade pure still residues.

In the practice of the present invention the pure still residues are subjected to distillation to.

remove a portion of the residual oils, whereupon the product is ready for use as a thermo-plastic binder in the manufacture of mastic floor tile in accordance with this invention. The exact amount of oil to be removed from the pure still residues will depend upon the properties desired in the binder. In general it may be said, however, that as the removal of the oils progresses the melting point of the product will become higher. Thus by control of the extent of oil removal the properties of the binder can be varied to suit particular needs.

These materials may be used as binders generally in the production of mastic floor tile irrespective of the particular fillers, or combinations of fillers, or pigments and colors, used in their production. The invention resides, not in the use of any specific filler, pigment or color, or proportions thereof, but in the bonding of all 30 such compositions with a thermo-plastic binder produced by removal of oil from pure still residues.

Thus it will be apprehended, from what has been said, that exact proportions of ingredients 35 can not be laid down for all purposes because these will vary with the materials used and the properties requisite in the tile. The same thing applies to the extent of removal of oil from the pure still residues in treating them to produce the 0 binder used in the practice of the invention.

However, as exemplifying the practice of the invention, mastic floor tile may be made from a composition of 21 parts of limestone dust and 34 parts of asbestos as fillers, 1 part of color, and 18 best embodiment.

parts of a binder formed by distillation of pure still residues as described above.

The ingredients are combined in any suitable manner, as by means of a Banbury mixer, and the resulting heated plastic mix is worked 6 through sheeter rolls and calender rolls in the usual sequence, followed by cutting to size.

According to the provisions of the Patent Statutes, we have explained the principle and manner of practicing our invention and have de- 10 scribed What we now consider to represent its However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

We claim:

1. A mastic floor tile composition comprising filler, and a thermo-plastic binder comprising material produced by distillation of oil from pure still residues resultant from fractionation of light 20 oil recovered in by-product coke oven operation.

2. A mastic floor tile composition comprising filler, and a thermo-plastic binder comprising material that is substantially non-saponifiable and contains inorganic matter, and is produced 25 by distillation of oil from pure still residues resultant from fractionation of light oil recovered in by-product coke oven operation.

3. A mastic floor tile composition comprising filler, color, and a th'ermo-plastic binder comprising material produced by distillation of oil from pure still residues resultant from fractionation of light oil recovered in by-product coke oven operation.

4. A mastic floor tile composition comprising about 21 parts of limestone dust, about 34 parts of asbestos, 1 part of color and about 18 parts of a product obtained by distillation of oil from pure still residues resultant from fractionation of light oil recovered in by-product coke oven 0 operation.

JOSEPH RIVKIN. ROBERT C. SCHEIB. 

